#KYJ Bronchiolitis in 2018
Bronchiolitis
Dispelling the myths that we should do what we do because it’s the way it’s always been done.
Background.
The smallest airways are bronchioles. They connect the big airways (bronchi) with the air sacs (alveoli) where oxygen and CO2 do-si-do .
Bronchioles have mucous coated meaty walls with abundant smooth muscle . They actually constrict and relax to change diameter and regulate air flow. Remember that pearl- we will use that later on.
When inflamed (Bronchiolitis) they swell and constrict, which results in restricted air flow, causing the person to have an increased work of breathing. That is ok in mild bronchiolitis in fit older children or adults, but in babies or toddlers, these wee tikes get exhausted (the struggle is real). Apnoea or respiratory arrest is the feared complication in severe bronchiolitis.
Now it comes in two flavours. Allergic bronchiolitis, and infective bronchiolitis. Both are swollen restricted airflow. Both cause increased work of breathing.
Infective Bronchiolitis is the most common reasons for babies to be admitted to hospitals in our region (Aust/NZ). As the name implies, infective Bronchiolitis is caused by a pathogen, almost certainly viral, but far more rarely, bacteria.
With allergic Bronchiolitis the trigger is some substance other than a pathogen. It might be milk, egg, pollen, dust mite, or any number of triggers. This stimulates an immune response where histamine is released, swelling and mucous is produced, and unique to Allergic Bronchiolitis (Asthma by another name - but don’t call it that prior to the 3rd birthday), unique to this pathodrome is the feature of dominant bronchospasm. Remember those smooth muscles? Yeah, they constrict, strangling the bronchioles worsening air flow.
Ok... still with me?
48% of infants admitted to Australian hospitals with bronchiolitis receive treatment that has no evidence of benefit (Davis , 2018).
You may know Tessa a Paediatrician who runs a great paeds SoMe called
#DontForgetTheBubbles
She writes that the PREDICT network have conducted a systematic review to produce Australia’s first bronchiolitis guideline .
Investigations
Recommended
•Urine M/C/S (if under 2 months old and febrile)
•Monitor Sats (spO2)
•Monitor work of breathing
Not recommended
•Routine blood
•Routine urine testing
•Viral swabs
Treatments
•Hydrate the kid. Oral,NG or IV
•Oxygen in children sating at or below 91%
Not recommended
•Oxygen if Sats are >91% (prolongs stay)
•Salbutamol- May worsen
•Steroids eg Predmix
•Saline nebs
•Adrenaline nebs
•Nasal saline drops
•Antibiotics -more harm than good
Now let’s look at these #CageRattlers.
A common feature of allergic bronchiolitis is bronchospasm, but that is not a common feature of chest infection, so salbutamol, adrenaline or other bronchodilators are not helpful. In viral chest infection, antibiotics are only effective when it if the child gets an opportunistic bacterial infection on top. And to suppress their immature immune system using steroids is asking for bacteria and thrush to come to the puffer-party.
So the key here is differentiating between an Asthma like presentation where steroids and salbutamol are indicated, and an infective bronchiolitis where they aren’t recommended as routine.
All in all an interesting summary with a bit of dogma busting along the way.
For a more comprehensive look
Click here: Davis, T. Bronchiolitis guidelines, Don't Forget the Bubbles, 2018. Available at:
http://doi.org/10.31440/DFTB.17023
